Analysis of the impact of GZMK on RFS in breast cancer patients showed that in all breast cancer patients (n = 4929 cases), the high expression group of GZMK (n = 2464 cases) had better RFS than the low expression group (n = 2465 cases), with statistical significance (HR = 0.78 (0.71–0.87), P < 0.001) (Figure S4A); similar findings were observed in the analysis of different subtypes of breast cancer (Figure S4). The gene discussed is GZMK; the disease is breast cancer.